Determination of Sulphated Ash
Equipment : 1.Silica or Platinum crucible.
a silica or platinum crucible to redness for 10 minutes, allow to cool in a
desiccator and weigh.
Take 1.0 gm of the substance and weight the crucible .
Ignite, gently at first, until the substance is thoroughly charred.
moisten the residue with 1 ml of Sulphuric acid , heat gently until the white
fumes are no longer evolved and ignite at 8000 ± 250C
until all black particles have disappeared.
Conduct the ignite in a place
protected from air currents.
Allow the crucible to cool, add a few drops of
Sulphuric acid and heat.
Ignite as before, allow to cool and weigh.
operation until two successive weighing do not differ by more than 0.5 mg.